Advertising: 01622 699116 Editorial: 01354 461430


Sandy Damm, Managing Director at Sontay, takes a look back at the origins of the


humble sensor and how it continues to play a pivotal role in understanding building efficiency.


ENERGY MANAGEMENT BSEE


SENSORS AND BUILDING EFFICIENCY Are sensors the forgotten heroes of BMS?


energy saving control techniques, such as optimum start and dead bands, with communication and information systems that allow active management of the building services and the capability to achieve and maintain a high level of energy efficiency and lower carbon emissions.


B ‘


Increasingly popular wireless sensor technology is having a fundamental impact in transforming how we think about the cost of sensor installation. By eliminating the need for structural cabling during sensor installation, wireless devices such as our SonNet family can greatly reduce engineering time and installed project cost.


’


For all the sophistication, advanced feature-sets and benefits that these control systems bring to their occupants, they are dependant for their success upon the humble sensor. Room temperature and humidity sensing and transmitting products began in conjunction with the development and proliferation of centralised building management systems in the 1980s. Right from their original introduction as the eyes and ears of the BMS, misconceptions have persisted in terms of how accurate these devices really need to be, how fast they should react and what precisely constitutes a high quality room and/or duct sensor. These factors are important and they demand closer consideration from consultants, contractors and systems integrators charged with delivering energy efficient control systems for today’s buildings. As an example, many consulting engineers continue to specify 0-10V transmitters equipped with PT100 type temperature elements, as standard. The commonly held view is that these products are more accurate than box- standard thermistors. In fact, quite the opposite is true. Thermistors are today available in different grades and types which quite often exceed the accuracy of transmitters of old. Measurement accuracy versus stability is another talking point. Generally speaking, the industry has relied and continues to rely on temperature sensors which are low cost and tolerate +/- .3 degrees Celsius over the entire range (-10 to +70). As a result, this has become the specification standard within the UK market. But what is really important from a sensing perspective is longer term stability rather than absolute accuracy. It is much more important for devices to remain accurate within the manufacturer’s specification (+/- .3 degrees) for the life of the device than their absolute accuracy. After all, these devices are being applied within commercial buildings to enhance occupant comfort and improve energy savings over the long term. If our balance of priorities shifts in favour of performance stability over absolute accuracy then these benefits can be successfully realised.


Aesthetics


Today, changing aesthetics and increased functionality are important drivers in helping us re-evaluate the way that we look at sensors.


Until now, sensors have been selected with little or no regard to design aesthetics. The latest devices offer an opportunity for specifiers not simply to satisfy the functional demands of their


VISIT OUR WEBSITE: www.bsee.co.uk


uilding Management Systems (BMS) have been a big success story in UK commercial buildings over the last 25 years. They combine


client but also the impact of the sensor on the interior space, and the look and feel of these devices.


Room sensors are now being specially designed with low profile and curved fascia to ensure that they can blend stylishly and seamlessly into a room’s design scheme whilst still helping to deliver greater energy efficiency, cost savings and carbon reductions in new build and retrofit building applications. The bland and, frankly, cheap-looking design of the ordinary room sensor need no longer be a barrier nor an unwanted intrusion into the design scheme of the upmarket commercial office building.


The cost of sensors also remains an issue but it is important not to just go for the cheapest option. Different price- points often reflect a differential in quality. Choosing the lowest cost sensor brings with it the increased risk of compromising on long-term measurement reliability and performance stability. Device failure can lead to the time and cost of unnecessary call out and product replacement issues, alongside the unwanted cost of reputational damage to the specifying contractor and consultant.


Increasingly popular wireless sensor technology is having a fundamental impact in transforming how we think about the cost of sensor installation. By eliminating the need for structural cabling during sensor installation, wireless devices such as our SonNet family can greatly reduce engineering time and installed project cost. This enables faster and easier installation on new buildings and also opens up the opportunity for control specialists to retrofit energy efficient HVAC controls into existing commercial and public buildings.


Wireless technology


Seamless integration of wireless technology is essential and making sensors compatible with current building control systems aids this process. For example, our RF-IOM-4A-4U input/output module works in conjunction with SonNet sensors and routers and acts as a local I/O with connectivity to typical HVAC equipment, such as fan coil units or variable air volume boxes. The module can take any 0-10Vdc, 4-20mA, resistive or VFC signal from wired devices in the field and transmit them to one of SonNet RF-RX receivers which in turn communicate the information to controller. The strategy within the controller uses this information to calculate control values, which are then passed back through the I/O module to alter damper positions and other output connections in the field. In the early years, SonNet receivers collected data from the network and communicated them in 0-10Vdc output to the controller. Over time a receiver compatible with a JACE controller through a Niagara framework was developed and shortly after a gateway called SIP was launched making SonNet network compatible with Trend systems. Sontay also launched a RF-RXS-B SonNet receiver, which allows easy integration to BACnet controllers.


The growth in IoT compatible devices is also playing a vital role in improving


uSmart Temperature Controllers offer tight control of heating, cooling and ventilation demand in modern building control systems such as hotels or office buildings.


functionality. Sensors are inherently smart, measuring, analysing and evaluating a variety of building performance data and making this information available to the control system. If all the data they collect is read and acted upon, we can improve energy management, facilitate better maintenance and repair regimes, and help end-users improve how they utilise their buildings.


To make the system as smart as possible you need connected devices and we are seeing a high number of devices and control systems using the internet protocol alongside traditional protocols for communication, such as BACnet and Modbus.


BACnet or Modbus networks are very common in the UK but very few sensing devices communicate directly with these protocols. This means that system integrators would need to install a gateway to connect the whole system. By selecting a sensor that can communicate with either protocol, it makes systems easier to connect, configure and operate. They will also save on installation time and provide better communication with the rest of a buildings control system, helping it to make intelligent choices.


For example, the new Sontay SC-ST Smart temperature controller will interact directly with HVAC devices (heating/cooling or fanspeed) via BACnet protocol. It can be configured remotely via BACnet or locally on the device itself. Sontay has also recently launched a new SonNet BACNet receiver, which automatically maps data from SonNet sensors into BACnet objects and can transmit data them via the vendor independent BACnet IP communication protocol, using a simple web browser interface. Today’s sensing devices are providing much better aesthetics and greater functionality for a relatively low total installed cost. These devices are capable of providing a better picture of the true building conditions over a long term in smaller, more pleasing to the eye packages. The result is the creation of a broader market opportunity for control systems specifiers and installers and, ultimately, the potential for more energy efficient buildings and reduced carbon emissions for all.


www.sontay.com ‘ Until now, sensors have been selected with


little or no regard to design aesthetics. The latest devices offer an opportunity for specifiers not simply to satisfy the functional demands of their client but also the impact of the sensor on the interior space, and the look and feel of these devices.


’ BUILDING SERVICES & ENVIRONMENTAL ENGINEER AUGUST 2017 27


uSonNet Wireless receivers allow quick and seamless integration of SonNet devices into building management systems. The RF‐RXS‐B automatically maps data from SonNet end devices into BACnet objects which are transmitted via the vendor independent BACnet IP communication protocol, using a simple web browser interface.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40